Aerosol type dispenser

ABSTRACT

An aerosol dispenser for dispensing fluids under pressure in which the dispenser has a spiral restricted passage between the dip tube and valve and through which the fluid to be dispensed passes when the valve is opened, the number of spirals in the restricted passage being not less than one and not more than 100, preferably between six and 50, and the diameter of such restricted passage being such that the fluid is retained therein, except when being dispensed, by capillary action.

United States Patent 1 1 Mil il Lazarus 1 Jan. 16, 1973 54] AEROSOL TYPEDISPENSER 3,412,937 11/1968 Chamberlain ..239/4ss x Inventor: Stokes S.va a us, Crestview Wilkins Road, Harrisburg, Pa. 171 12 PrimaryExaminer-Robert B. Reeves plied: J 1, 1970 Assistant ExaminerJ0hn P.Shannon, Jr. 21 APPL 42 090 Attorney-Morgan, Finnegan, Durham & PineRelated (1.8. Application Data 57 I ABSTRACT continuation'in-pan of763,189, p An aerosol dispenser for dispensing fluids under pres- 1968.sure in which the dispenser has a spiral restricted passage between thedip tube and valve and through [2%] US. Cl ..222/402.24 which the fluidto be dispensed passes when the valve is p the number Spirals in therestricted 1 o 233;?igy zgfgfz passage being not lessthan one and notmore than 2 100, preferably between six and 50, and the diameter v ofsuch restricted passage being such that the fluid is [5.6] ReferencesCited retained therein, except when being dispensed, by

UNITED STATES PATENTS capillary action 3,217,937 11/1965 Kasparian..222/ 146 HA 5 Claims, 5 Drawing Figures PATENTEDJAN 16 ms (1%. 7 10.990

20 4'0- 0 80 DIAMETER or 4 STRAIGHT ma /2 F IG.4

0246'8I'OI2I4I6 FIGS NUMBER OF CUILS qgwmnmmamwemmimre ATTORNEYS AEROSOLTYPE DISPENSER This application is a continuation-in-part of U.S.Application Ser. No. 763,189, filed Sept. 27, 1968 and relates toaerosol dispensers and, more particularly, to

of the liquid in such dispenser may be discharged before the dispenseris discarded. Such dispenser may be used a number of times before thecontents are exhausted and the dispenser is discarded.

Aerosol dispensers are utilized for packaging and dispensing a widevariety of liquids. When the dispensing valve is actuated, usually bydepressing the stem of the valve extending outwardly from the top of thedispenser, the liquid is sprayed out of the dispenser, usually throughan orifice in the valve stem. The liquid is discharged through and outof the orifice in a spray pattern. With some materials, for examplequick drying hair sprays, the uniformity of this spray pattern and thesize of the liquid particles in the pattern sprayed are of particularimportance. Variations in such pattern and variations in the size of theliquid particles while, from time to time, the contents of the dispenserare being used, can adversely effect the spray application of the liquidand the effectiveness of such liquid. For example, if the dispenser isheld at the same distance from the hair being sprayed with quick dryinghair spray and the spray pattern in one application differsfrom thespray pattern in another application, the amount of sprayed liquidapplied and the drying thereof will vary. Likewise, if from applicationto application the liquid particle size varies, the amount applied anddrying will var \yarious attempts have, heretofore, been made to improvethe spray pattern and uniformity of the particle size of liquids sprayedfrom aerosol dispensers. Such attempts have included arrangements in thevalves, the orifices and the internal diameter of the dip tube. Sucharrangements have been expensive, tended to clog or otherwise adverselyeffect dispensing or, for a variety of reasons, have been found to beimpractical.

In the instantinvention, it has been discovered that be described inmore detail, may be in the form of a pin or boss extending into thedispensing valve end of the dip tube or a spiral accordianed sleeve inthe valve body chamber.

In the instance of the pin or boss, the outer surface is provided with aspiral groove communicating, at one end, with the ID. of the dip tubeand, at its other end,

with the dispensing valve chamber. Such pin or boss may be molded as anintegral part of the valve chamber housing or may be formed separatelyand inserted into the valve end of the dip tube. In either event, aswill be later described, the spiral groove on the outer surface of thepin or boss and the inner wall of the dip tube cooperate to form thespiral or convolute passage of restricted size.

Where the spiral or convolute passage is in the form of a spiral,accordianed sleeve in the valve body chamber, the sleeve fits into andcooperates with the inner wall of the valve body chamber so as to form,with such inner wall, the desired spiral or convolute passage ofrestricted size. In this embodiment, as will be more fully described,the accordianed sleeve may also act as the spring for the valve. Thus,the sleeve, made from a resilient plastic, is compressed when thedispensing valve is opened and, when the valve is released, expands toclose the valve. Because the liquid to be dispersed will pass throughthe spiral or convolute passage only when the valve is open and suchsleeve is compressed, the spiral opening in such sleeve should be ofsufficient size so that, when the dispersing valve is opened and thesleeve is compressed, the spiral passage will be of sufficient size topermit the required restricted flow.

The internal diameter of the spiral or convolute passage in the instantinvention will depend upon the liquid to be dispersed, the viscosity ofsuch liquid at the dispensing temperature, usually F. the prevailingtemperature at which aerosol dispensers are used, and similar factors.For purposes of the instant invention, the internal diameter of thespiral or convolute passageway is of such size that the liquid will beheld in such passageway by capillary action.

The substantial improvements in the uniformity of spray pattern anduniformity of particle size, afforded by the instant invention, resultin a more uniform rate of discharge from the aerosol dispenser extendingover the life of such dispenser. Likewise, the spray pattern and mixtureremain more uniform over the life of such dispenser. The maintenance inuniformity of the mixture can be of substantial importance where, as inthe instance of a quick drying hair spray, such mixture, if not uniformcan become flammable Additionally, in the instant invention, theentrainment and discharge of the propellant propellant gas is avoidedand the liquid,

as it is discharged, is maintained in equilibrium. Higher pressure,lower cost propellant gases, such as CO and NiO can be substituted forhigher cost Freon. The latter is of substantial importance because ofthe cost reduction effected.

The exact theory of the improvements of the instant invention, otherthan in performance and costs, is not known. It is believed, however,that Newtons Laws, as applied to circular motion, and Bernoulis Theorem,and the increased frictional flow and turbulent flow afforded thereby,combined to provide an infinite number of expansion changes along thespiral or convolute tube passage. Thus, the flow path with the spiral orconvolute tube of the instant invention is increased between about 2 toabout 24 micro-seconds as compared to a straight tube of the sameinternal diameter but without the spiral or convolute portion. Theincrease in flow path time will, of course, depend upon the number ofspirals. The number of spirals may be as low as one or in excess of 100.For most liquids, six to 50 spirals are preferred.

The instant invention will be more fully described and better understoodin the following description of preferred embodiments of the inventiontaken with the appended drawing in which:

FIG. 1 is a view, partly broken away, of one embodiment of theinvention;

FIG. 2 is an enlarged view, in section, of the embodiment of FIG. 1;

FIG. 3 is an enlarged view, similar to FIG. 2 but showing a secondembodiment of the invention;

FIGS. 4 and 5 are graphs showing the effects of tube diameter and thenumber of coils in the spiral on the size of particles, with the size ofthe particles measured in microns and the internal diameter of the tubemeasured in thousands of an inch.

Referring to the drawings, particularly FIGS. 1 and 2 showing one of theembodiments of the invention, the dispenser comprises container 2,usually a metal can, having a cap 4,- crimped or otherwise suitablyfixed to container 2. Cover 6 is removably attached to container 2 byshoulder 8, the cover extending over the upper end of valve button 10 toprevent accidental displacement of the valve when cover 6 is in place,as is conventional on the type of aerosol container illustrated. Y

With particular reference to FIG. 2, valve chamber housing 12 and valvechamber cover 14 are held in fixed position in cap 4. Pin 16, which,preferably, is formed as an integral part of housing 12, but may beaseparate unit, extends downwardly, from housing 12, into dip tube 18.Around its periphery, pin 16 has a spiral groove 20, connected, at itslower end by passage 22 with the interior of dip tube 18 and, at itsupper end, by passage 24 with the interior of valve chamber housing 12.As willbe later described, spiral groove 20 and the interior wall of diptube 22 form a spiral passageway between dip tube 22 and the interior ofvalve chamber housing 12.

Valve 30 is held in seated engagement with valve chamber cover 14 bycompression spring 32. Stem 34, which is hollow, of valve 30 extendsupwardly into valve button 10. At its lower end, stem 34 has a pluralityof ports 36 which, when valve 30 is opened, permit liquid to pass fromcontainer 2 through stem 34 and to be discharged through orifice 38 invalve button 10.

With the exception of pin 16, groove 20 and passages 22, 24, theconstruction of the aerosol dispenser of FIGS. 1 and 2 are conventional.The contents of container 2, under pressure in such container, aresprayed out through orifice 38 when cover 6 isremoved and valve button10 is depressed.When valve button 10 is released, valve 30 is closed byspring 32, cutting off the discharge of spray through orifice 38.

As has been noted, the internal diameter of the spiral or convolutepassageway formed by groove 20 and the inner wall of clip tube 18 is,preferrably, of such size that the liquid to be dispensed will be heldin such passageway by capillary action. Larger passageways, while theyafford some of the advantages of the instant invention, in the instanceof many liquids to be dispensed, do not afford the full advantages.

the turbulence in such flow. Hence, the pressure drop exists on agreater volume of liquid or fluid for a longer length of time .which, inturn, increases the amount of gas being released in the liquid. Theangular velocity imparted by the spiral or convolute configuration ofthe passageway exerts g forces on the flowing fluid, increasing thetemperature of such fluid and the turbulence therein. Velocity may be ashigh as 300 feet per second, or higher, and result in greater reductionin pressure so that the liquid may be said to be supersaturated with thepropellant gas. Turbulence helps to disperse the liquid and the gas andto release the gas from the liquid.

The reduction in internal diameter, alone, reduces particle size. Thisis best shown in FIG. 4 where the diameter of a straight tube inthousands of an inch are plotted against particle size in microns wherepercent of the particles in the spray are smaller than the indicatedparticle size on the graph. In FIG. 5, the effect of the number of coilson particle size is shown. In formulating the data for both graphs aliquid base of ethanol and a propellant of diflucrodichloro methane wasused. In the instance of FIG. 5, the internal diameter of the coilpassage was 0.030 inch with a coil diameter of five-eighths inch. Thesedimensions, however, should not be taken as indicative of preferreddimensions in the apparatus of the instant invention. Such dimensionswill vary from liquid to liquid, propellant gas to propellant gas,internal container pressure, temperatures and similar variables. Thesetests do show,

however, the improvements to be attained in the instant invention andthe synergistic effects thereof.

Referring now to FIG. 3 showing a second embodiment of the instantinvention, the spiral or convolute passageway in the fluid passage flowfrom dip tube 18 to the valve is combined in an accordianed member invalve chamber housinG 12, thereby combining the spirai or convolutepassageway with the spring for clos-- ing the valve and eliminatingthespring, as in FIG. 1, as a separate element. In FIG. 3, accordian sleevemember 50, having spiral groove 52 along its outer wall is fitted intovalve chamber housing 12 so that the inner wall of housing 12 and spiralgroove 52 form a spiral passageway opening, at one end, through passage54, into dip tube 18 and opening, at the other end, into the upper endof valve chamber housing 12. Accordian sleeve member 50 is of resilientmaterial, such as plastic, which, as valve 30 is opened by depressingbutton 10, is compressed and, when button 10 is released,

the features shown and described or portions thereof, but it isrecognized that various modifications are possible.

What is claimed is:

1. An aerosol dispensing pressure container having a dip tube immersedat one of its ends In the liquid in said container to be dispersed andconnected at its opposite end to a valve which, when open, allows saidliquid in said container to pass through said clip tube and be dispensedand, when closed, maintains said liquid under pressure in said dip tubeand said container, a spiral passageway member at the valve end of saiddip tube in which said spiral passageway member is a resilient accordianmember seated, at one of its ends, against said valve seat and seated,at its opposite end, against a wall of the valve housing and formingbetween said valve and said wall a resilient member for closing saidvalve.

2. An aerosol dispensing pressure container, as

recited in claim 1, in which said spiral passageway member has a spiralgroove extending along its outer wall, said spiral groove and the innerwall of said valve housing forming said spiral passageway forrestricting the flow of said liquid when said valve is open.

3. An aerosol dispensing pressure container, as recited in claim 2, inwhich said spiral passage is of a diameter in which the liquid in saidcontainer will be retained by capillary action.

4. An aerosol dispensing pressure container, as recited in claim 3, inwhich the number of spirals in said spiral passage are not less than oneand not more than 100.

5. An aerosol dispensing pressure container, as recited in claim 4, inwhich the number of spirals in said spiral passage are not less than sixand not more than

1. An aerosol dispensing pressure container having a dip tube immersedat one of its ends In the liquid in said container to be dispersed andconnected at its opposite end to a valve which, when open, allows saidliquid in said container to pass through said dip tube and be dispensedand, when closed, maintains said liquid under pressure in said dip tubeand said container, a spiral passageway member at the valve end of saiddip tube in which said spiral passageway member is a resilient accordianmember seated, at one of its ends, against said valve seat and seated,at its opposite end, against a wall of the valve housing and formingbetween said valve and said wall a resilient member for closing saidvalve.
 2. An aerosol dispensing pressure container, as recited in claim1, in which said spiral passageway member has a spiral groove extendingalong its outer wall, said spiral groove and the inner wall of saidvalve housing forming said spiral passageway for restricting the flow ofsaid liquid when said valve is open.
 3. An aerosol dispensing pressurecontainer, as recited in claim 2, in which said spiral passage is of adiameter in which the liquid in said container will be retained bycapillary action.
 4. AN aerosol dispensing pressure container, asrecited in claim 3, in which the number of spirals in said spiralpassage are not less than one and not more than
 100. 5. An aerosoldispensing pressure container, as recited in claim 4, in which thenumber of spirals in said spiral passage are not less than six and notmore than 50.